/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.biff.formula;

import jxl.common.Logger;

/**
 * Abstract base class for an item in a formula parse tree
 */
abstract class ParseItem {
    // The logger
    private static Logger logger = Logger.getLogger(ParseItem.class);

    /**
     * The parent of this parse item
     */
    private ParseItem parent;

    /**
     * Volatile flag
     */
    private boolean volatileFunction;

    /**
     * Indicates that the alternative token code should be used
     * @deprecated - use the ParseContext now
     */
    private boolean alternateCode;

    /**
     * Indicates that an alternative token code should be used
     */
    private ParseContext parseContext;

    /**
     * Indicates whether this tree represents a valid formula or not.  If not
     * the parser replaces it with a valid one
     */
    private boolean valid;

    /**
     * Constructor
     */
    public ParseItem() {
        volatileFunction = false;
        alternateCode = false;
        valid = true;
        parseContext = parseContext.DEFAULT;
    }

    /**
     * Called by this class to initialize the parent
     */
    protected void setParent(ParseItem p) {
        parent = p;
    }

    /**
     * Sets the volatile flag and ripples all the way up the parse tree
     */
    protected void setVolatile() {
        volatileFunction = true;
        if (parent != null && !parent.isVolatile()) {
            parent.setVolatile();
        }
    }

    /**
     * Sets the invalid flag and ripples all the way up the parse tree
     */
    protected final void setInvalid() {
        valid = false;
        if (parent != null) {
            parent.setInvalid();
        }
    }

    /**
     * Accessor for the volatile function
     *
     * @return TRUE if the formula is volatile, FALSE otherwise
     */
    final boolean isVolatile() {
        return volatileFunction;
    }

    /**
     * Accessor for the volatile function
     *
     * @return TRUE if the formula is volatile, FALSE otherwise
     */
    final boolean isValid() {
        return valid;
    }

    /**
     * Gets the string representation of this item
     * @param ws the workbook settings
     */
    abstract void getString(StringBuffer buf);

    /**
     * Gets the token representation of this item in RPN
     *
     * @return the bytes applicable to this formula
     */
    abstract byte[] getBytes();

    /**
     * Adjusts all the relative cell references in this formula by the
     * amount specified.  Used when copying formulas
     *
     * @param colAdjust the amount to add on to each relative cell reference
     * @param rowAdjust the amount to add on to each relative row reference
     */
    abstract void adjustRelativeCellReferences(int colAdjust, int rowAdjust);

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was inserted
     * @param col the column number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    abstract void columnInserted(int sheetIndex, int col, boolean currentSheet);

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the column was removed
     * @param col the column number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    abstract void columnRemoved(int sheetIndex, int col, boolean currentSheet);

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the row was inserted
     * @param row the row number which was inserted
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    abstract void rowInserted(int sheetIndex, int row, boolean currentSheet);

    /**
     * Called when a column is inserted on the specified sheet.  Tells
     * the formula  parser to update all of its cell references beyond this
     * column
     *
     * @param sheetIndex the sheet on which the row was removed
     * @param row the row number which was removed
     * @param currentSheet TRUE if this formula is on the sheet in which the
     * column was inserted, FALSE otherwise
     */
    abstract void rowRemoved(int sheetIndex, int row, boolean currentSheet);

    /**
     * If this formula was on an imported sheet, check that
     * cell references to another sheet are warned appropriately
     */
    abstract void handleImportedCellReferences();

    /**
     * Tells the operands to use the alternate code
     *
     * @deprecated - use setParseContext now
     */
    protected void setAlternateCode() {
        alternateCode = true;
    }

    /**
     * Accessor for the alternate code flag
     *
     * @return TRUE to use the alternate code, FALSE otherwise
     * @deprecated - use setParseContext now
     */
    protected final boolean useAlternateCode() {
        return alternateCode;
    }

    /**
     * Tells the operands to use the alternate code
     *
     * @pc the parse context
     */
    protected void setParseContext(ParseContext pc) {
        parseContext = pc;
    }

    /**
     * Accessor for the alternate code flag
     *
     * @return the parse context
     */
    protected final ParseContext getParseContext() {
        return parseContext;
    }

}



